六类布线时代的到来...

<p><b>&nbsp;&nbsp;&nbsp; 六类布线出来已久，但市场一直没普及开。到今年我想市场占有量应该有个质的飞跃吧。不知大家是否有同感，因此，今天把以前的精华帖转出来让大家再温习一下。</b></p><p><b>六类布线十五问</b>
        </p><div id="textstyle_111629" style="MARGIN-TOP: 10px; FONT-SIZE: 9pt; MIN-HEIGHT: 200px; WORD-BREAK: break-all; TEXT-INDENT: 24px; LINE-HEIGHT: normal; WORD-WRAP: break-word;">一、 为什么需要六类产品所提供的应用频宽？<br/><br/>答：带宽可比喻为高速公路，必须先提供足够的带宽才能增加数据速度，将带宽提升2倍亦等同将公速的行车线加倍一样，过去数据速度的发展及未来需求预测显示每18个月数据速度会翻一倍。现今运行于1GB/S速度的应用已将超五类布线推向极限，随着串流多媒体应用的逐渐普及，数据速度的需求会不断增加，这正如90年代五类布线代替了3类布线，以满足不断增加的网络速度需求（如100BASETX）（注：频宽的定义为ACR值显示大于0的最高频率）。<br/><br/>二、 超五类与六类产品的基本区别是什么？<br/><br/>答：超五类与六类产品的基本区别在于传输性能及频宽的提高。超五类的频宽是100MHZ；包括NEXT（近端串扰）、RETURN LOSS（回波消耗）及ELFEXT（等效远端串扰）等传输性能的改善可大大提高ACR值，从而提高应用的稳定性及使系统传输速度得以提高。<br/>　　<br/>三、 六类产品相对于超五类产品有什么优点可提高网络性能表现？<br/><br/>答：由于传输速度的改善及超越的防干扰性能，六类产品相比超五类产品更能有效地减少误码率，从而减少因丢失数据包而需要重覆传输的情况，大大提高网络的稳定性。<br/><br/>四、 六类电缆与接插件是否需要互相匹配使用才能组成一个“和谐”的布线系统？<br/><br/>答：有部分布线生产厂家提倡“和谐”布线系统，以提高系统的余量表现，但这个概念至今并未收纳于六类标准规范中。理论上，TIA标准只要求每个部件都要单独通过6类标准，则可确保良好的链路或通道表现。<br/><br/>五、 可否不采用六类电缆而直接采用光纤电缆？<br/><br/>答：你当然可以这样做，但是光纤系统极为昂贵，而价格往往是客户决定因素，现今光纤布线系统的成本为六类布线的2倍。同时安装铜缆也比安装光缆简单。除此之外，铜缆产品亦支持IEEE（802.3af）正在草定的DTE标准。<br/><br/>六、 什么是电气平衡？<br/><br/>答：对两根铜丝所组成的电路被视为一个既完整又平衡的传输线路，一个完整线路于整个传输通道中有着同一电气性能，而一个平衡线路里的2根铜线有着相同的电气特性，“电气平衡”泛指一对铜缆的物理结构及介质特性。若1对铜线的直径，同心度，导电材料基本相同长度亦一致，那么，这对电缆相对于外间环境可被视为电气平衡。电气平衡的程度视乎电缆的设计及生产过程，而六类电缆对秤过程的精密度有着很高的要求，同样地六类接插件亦需要一个平衡线路设计，于一个平衡传输中，若相反电极的同等电压加设于电线的两端，电流所产生的磁场会相互抵消而不会向外发出干扰，同样道理，2根铜体所受到的外界干扰亦很少，因为一个外来的干扰会与一对铜芯的每一导体上产生电极相同的同等电压，而2根铜芯的电压差别基本是0。而讯号干扰源于2根铜芯讯号的差别，故此，外来的干扰对于平衡传输有着很小影响。而电气平衡程度主要视乎电压差别，并以DB作为量度单位，于六类标准，这个数被称为LCL。<br/><br/>七、 安装商可否自己制造跳线？<br/><br/>答：有如六类电缆及接插件，六类跳线是高精密产品，需要在极为稳定的环境下生产及测试，以确保产品的性能表现，所以TIA标准，建议六类跳线应用于工厂内特定环境下控制生产，而不应用于安装现场随便制作而成。<br/><br/>八、 超五类与六类接插模块是否有很大的区别？为何六类模块这么昂贵？<br/><br/>答：虽然外表上六类与超五类模块没有多大的区别，但六类模块有更高的传输性能。例如：在100MHZ范围下，一 个超五类模块的NEXT值是43db,而六类模块的值是54db。换句话说，一个超五类模块相比于六类模块会产生12倍的噪音，而这个性能改善有赖于科技的改进、生产程序的改善、物料的控制等，以致大大增加成本。<br/><br/>九、 是否需要采用厂家的六类跳线才能保证系统性能？<br/><br/>答：TIA标准对六类跳线及接插件要求都有所规范，只要产品能通过六类部件及通道标准要求。整个系统应该可以达到六类标准，而很多厂家为了提高系统的性能余量，会特别生产阻搞匹配的电缆接插件及跳线，以大大提高系统的传输性能余量。<br/><br/>十、 是否可以将不同厂家的六类产品混合使用？<br/><br/>答：如果系统内的每个组件都合乎六类部件及通道的要求，理论上，不同厂家产品组成的布线系统亦应可通过 六类测试。<br/><br/>十一、按照400MHZ测试的超五类电缆与按照250MHZ测试的六类电缆有何分别？<br/><br/>答：超五类标准规范了0-100MHZ以下超五类产品的各项电气性能表现。基本上，只要测试仪可支持的测试频率（如350MHZ或400MHZ）范围，你都可以在这个频率下测试产品的性能表现，但所有的测试结果相对于有关标准毫无意义，而六类标准则规范了0-250MHZ范围内电缆，接插件及跳线的有关通道及永久链路性能特性，确保于0-250MHZ应用上有着可靠的系统性能表现。<br/><br/>十二、超五类与六类接插模块是否有很大区别？为何六类模块这么昂贵？<br/><br/>答：虽然外表上六类与超五类模块没有多大的区别，但六类模块有更高的传输性能。例如：在100MHZ范围下，一 个超五类模块的NEXT值是43db,而六类模块的值是54db。换句话说，一个超五类模块相比于六类模块会产生12倍的噪音，而这个性能改善有赖于科技的改进、生产程序的改善、物料的控制等，以致大大增加成本。<br/><br/>十三、按照400MHZ测试的超五类电缆与按照250MHZ测试的六类电缆有何分别？<br/><br/>答：超五类标准规范了0-100MHZ以下超五类产品的各项电气性能表现。基本上，只要测试仪可支持的测试频率（如350MHZ或400MHZ）范围，你都可以在这个频率下测试产品的性能表现，但所有的测试结果相对于有关标准毫无意义，而六类标准则规范了0-250MHZ范围内电缆，接插件及跳线的有关通道及永久链路性能特性，确保于0-250MHZ应用上有着可靠的系统性能表现。<br/><br/>十四、TIA标准允许的最短链路是多少、<br/><br/>答：TIA标准里没有规范最短链路，理论TIA标准可允许任何不超过100M的通道链路，ANSI/TIA/EIA-568-B有提及过每一接点与通讯间的距离应保持15M以上，以减低接插器件于近端所产生的干扰，此建议是以一个4连接点的信道模型的最坏情况下所计算出来的最短链路距离。<br/><br/>　　十五、什么情况下应该考虑安装六类产品？<br/><br/>　　答：若考虑网络将来的应用需求，理论上应安装最先进的布线产品，因为安装电缆后往往难以重新更新替代，基本上，一个布线系统至少要应用10年作为标准，能够支持4至5年的网络设备的性能更新，如果将来的网络设备需要更好的电缆才能提高数据速度。那么，用六类电缆代替超五类电缆是无可避免的，但这些电缆重新组建工程非常昂贵，所以纵使六类产品的价格相对于超五类产品稍贵，但为了减少日后网络升级问题，六类产品仍然值得考虑。<br/></div>

<p>自己先做沙发，顶下</p>

问题挺全面~~顶一下~~嘿嘿

<p>很不错啊,摘抄了,谢谢啊.有好东东多拿出来点啊.</p>

南京兆通技术中心<br/><a href="http://www.ztwl.cn/technology.asp?table=jishu">http://www.ztwl.cn/technology.asp?table=jishu</a>

网络视频服务器<br/>网络摄像机<br/>视频服务器<br/>网络视频监控

<p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; WORD-BREAK: break-all; LINE-HEIGHT: 24pt; mso-pagination: widow-orphan;"><span style="FONT-SIZE: 10.5pt; COLOR: #333333; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<font color="#0909f7"><strong> 浅谈六类线的构造问题</strong></font></span><span style="FONT-SIZE: 10.5pt; COLOR: #333333; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;"><font color="#3809f7">&nbsp;<p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; WORD-BREAK: break-all; LINE-HEIGHT: 24pt; mso-pagination: widow-orphan;"><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;国际六类铜缆布线系统的标准主要包括了北美的</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">ANSI/TIA/EIA568B.2-1</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">，另外国际标准</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">ISO/IEC11801:2002</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">版本中也规定了</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">E</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">级布线系统的定义，两个标准颁布至今都已经超过</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">5</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">年，可以看到，在目前新建筑的布线选型中，六类</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">/E</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">级布线已经成为中高端国内用户的首选考虑。但同时经过十几年的发展，国内布线市场发展迅猛，竞争也愈加激烈，面对不同品牌、不同价格的六类方案，用户和集成商难免会有一些困惑，本文从常用的非屏蔽六类线缆结构的角度，简单介绍选型时应当注意的一些细节。主要从两个方面来说明：</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                                        <br/>1</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">．六类线缆内部支撑结构</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                                        <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　这个问题以前曾经引发过孰优孰裂的争论，即：十字骨架结构线</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;"> VS. </span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">一字隔离线，但在布线市场上还有某厂商推出的六类线内部是没有任何支撑结构的，所以应该是三种方式的比较。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                                        <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　六类线缆中采用</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">4</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">线对隔离装置是目前绝大多数布线厂家的选择，这种线缆内部带螺旋式十字支撑结构，将所有双绞线锁定在四个相对固定的位置，可有效降低在全频工作范围（</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">0</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">－</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">250MHz</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">）线对之间的相互干扰，具有稳定的平衡特性</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">,</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">实际施工环境下，能表现出良好的抗拉、抗挤压特性，像通常的</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">23AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">规格的十字骨架六类线缆在安装后会具有较高的、稳定的串扰衰减和阻抗等电气性能。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                                        <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　一字隔离带结构线缆内置一条分隔线，将</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">2</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">对双绞线与另</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">2</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">对分开，线对间的稳固性比十字结构差，实际施工中，这种结构容易由于施工因素：如折弯、扭绞、牵引力过大、绑扎过紧，产生线对位移问题，从而导致实际测试中电气性能余量低的现象。另外一字隔离带六类线缆的外径为</span></b><chmetcnv wst="on" unitname="mm" sourcevalue="6" hasspace="False" negative="False" numbertype="1" tcsc="0"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">6mm</span></b></chmetcnv><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">，采用十字骨架的六类线外径在</span></b><chmetcnv wst="on" unitname="mm" sourcevalue="6.3" hasspace="False" negative="False" numbertype="1" tcsc="0"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">6.3mm</span></b></chmetcnv><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">以内，对于非屏蔽线缆来讲，这点差距对管槽和弯曲半径的影响微乎其微，施工难度和成本也不会上升。值得注意的是，这种线缆正被同一厂家的十字骨架结构线缆所慢慢替代，说明其前途不被看好。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                                        <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　无任何线对支撑结构，采用</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">规格的所谓六类线缆，在市场上一直唱独角戏，应和者寥寥。本质上讲，它只能算是性能优良的超五类线缆，带宽性能在理想状态下可达到六类的</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">250MHz</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">，属于边缘产品，但由于实际施工现场不可能理想化</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">,</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">故在测试时，很容易由于线缆敷设或端接问题出现失败结果。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                                        <br/>2</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">．导线线径</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                                        <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　这是一个比较容易忽略的问题，布线市场上同样的六类十字骨架结构的线，铜芯线径往往有</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG(</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">标准</span></b><chmetcnv wst="on" unitname="mm" sourcevalue="0.511" hasspace="False" negative="False" numbertype="1" tcsc="0"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">0.511mm</span></b></chmetcnv><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">)</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">和</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">23AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">（标准</span></b><chmetcnv wst="on" unitname="mm" sourcevalue="0.573" hasspace="False" negative="False" numbertype="1" tcsc="0"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">0.573mm</span></b></chmetcnv><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">）两种指标，如果以一箱线的实际含铜量来比较，由于线径的粗细不同，</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">的六类线含铜量与</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">23AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">六类线含铜量的比值达到</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">1 : 1.25</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">，在市场售价上，两种线缆价格有不小的差距。很多用户和集成商对此区别没有注意，只是从价格上感觉某某品牌的六类线便宜。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                                        <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　国际六类布线标准中对于六类铜线的粗细规格定义了一个范围，如在</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">TIA</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">的六类标准中，就要求铜芯线径在</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">22AWG-24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">之间，故</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">规格是六类铜芯最低的标准。从这些线缆组合而成的链路及信道性能看，</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">23AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">的六类线所有的电气指标明显比</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">的六类线要高很多，带宽余量丰富，应用适应性更广。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                                        <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　不同的铜芯选择考虑其实代表着布线厂家的市场策略。在性能和价格的取舍上，出会出现这样的观点：只要是六类性能测试可以通过，就尽可能地降低成本。这也导致目前布线市场出现了一些性能较低的六类产品和方案。像某些厂家的六类线铜芯悄悄从</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">23AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">降至</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">，也是出于这种趋利的考虑。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                                        <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　我们认为，通过减少原材料的投入降低生产成本，以牺牲系统性能的代价来增强价格竞争力，是一种浮躁的短期现象，不利于布线企业长久健康发展。对于客户来说，在确定需求时，亦要根据自己应用的长远发展，合理规划定位真正性价比优良的布线系统。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;"><p></p></span></b></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" style="COLOR: blue; mso-fareast-font-family: 宋体; mso-fareast-language: ZH-CN;"><p><font face="Times New Roman" size="3">&nbsp;</font></p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; WORD-BREAK: break-all; LINE-HEIGHT: 24pt; mso-pagination: widow-orphan;"></p></font></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; WORD-BREAK: break-all; LINE-HEIGHT: 24pt; mso-pagination: widow-orphan;"><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;国际六类铜缆布线系统的标准主要包括了北美的</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">ANSI/TIA/EIA568B.2-1</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">，另外国际标准</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">ISO/IEC11801:2002</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">版本中也规定了</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">E</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">级布线系统的定义，两个标准颁布至今都已经超过</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">5</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">年，可以看到，在目前新建筑的布线选型中，六类</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">/E</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">级布线已经成为中高端国内用户的首选考虑。但同时经过十几年的发展，国内布线市场发展迅猛，竞争也愈加激烈，面对不同品牌、不同价格的六类方案，用户和集成商难免会有一些困惑，本文从常用的非屏蔽六类线缆结构的角度，简单介绍选型时应当注意的一些细节。主要从两个方面来说明：</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                <br/>1</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">．六类线缆内部支撑结构</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　这个问题以前曾经引发过孰优孰裂的争论，即：十字骨架结构线</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;"> VS. </span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">一字隔离线，但在布线市场上还有某厂商推出的六类线内部是没有任何支撑结构的，所以应该是三种方式的比较。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　六类线缆中采用</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">4</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">线对隔离装置是目前绝大多数布线厂家的选择，这种线缆内部带螺旋式十字支撑结构，将所有双绞线锁定在四个相对固定的位置，可有效降低在全频工作范围（</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">0</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">－</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">250MHz</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">）线对之间的相互干扰，具有稳定的平衡特性</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">,</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">实际施工环境下，能表现出良好的抗拉、抗挤压特性，像通常的</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">23AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">规格的十字骨架六类线缆在安装后会具有较高的、稳定的串扰衰减和阻抗等电气性能。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　一字隔离带结构线缆内置一条分隔线，将</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">2</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">对双绞线与另</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">2</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">对分开，线对间的稳固性比十字结构差，实际施工中，这种结构容易由于施工因素：如折弯、扭绞、牵引力过大、绑扎过紧，产生线对位移问题，从而导致实际测试中电气性能余量低的现象。另外一字隔离带六类线缆的外径为</span></b><chmetcnv wst="on" unitname="mm" sourcevalue="6" hasspace="False" negative="False" numbertype="1" tcsc="0"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">6mm</span></b></chmetcnv><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">，采用十字骨架的六类线外径在</span></b><chmetcnv wst="on" unitname="mm" sourcevalue="6.3" hasspace="False" negative="False" numbertype="1" tcsc="0"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">6.3mm</span></b></chmetcnv><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">以内，对于非屏蔽线缆来讲，这点差距对管槽和弯曲半径的影响微乎其微，施工难度和成本也不会上升。值得注意的是，这种线缆正被同一厂家的十字骨架结构线缆所慢慢替代，说明其前途不被看好。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　无任何线对支撑结构，采用</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">规格的所谓六类线缆，在市场上一直唱独角戏，应和者寥寥。本质上讲，它只能算是性能优良的超五类线缆，带宽性能在理想状态下可达到六类的</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">250MHz</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">，属于边缘产品，但由于实际施工现场不可能理想化</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">,</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">故在测试时，很容易由于线缆敷设或端接问题出现失败结果。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                <br/>2</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">．导线线径</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　这是一个比较容易忽略的问题，布线市场上同样的六类十字骨架结构的线，铜芯线径往往有</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG(</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">标准</span></b><chmetcnv wst="on" unitname="mm" sourcevalue="0.511" hasspace="False" negative="False" numbertype="1" tcsc="0"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">0.511mm</span></b></chmetcnv><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">)</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">和</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">23AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">（标准</span></b><chmetcnv wst="on" unitname="mm" sourcevalue="0.573" hasspace="False" negative="False" numbertype="1" tcsc="0"><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">0.573mm</span></b></chmetcnv><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">）两种指标，如果以一箱线的实际含铜量来比较，由于线径的粗细不同，</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">的六类线含铜量与</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">23AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">六类线含铜量的比值达到</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">1 : 1.25</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">，在市场售价上，两种线缆价格有不小的差距。很多用户和集成商对此区别没有注意，只是从价格上感觉某某品牌的六类线便宜。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　国际六类布线标准中对于六类铜线的粗细规格定义了一个范围，如在</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">TIA</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">的六类标准中，就要求铜芯线径在</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">22AWG-24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">之间，故</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">规格是六类铜芯最低的标准。从这些线缆组合而成的链路及信道性能看，</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">23AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">的六类线所有的电气指标明显比</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">的六类线要高很多，带宽余量丰富，应用适应性更广。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　不同的铜芯选择考虑其实代表着布线厂家的市场策略。在性能和价格的取舍上，出会出现这样的观点：只要是六类性能测试可以通过，就尽可能地降低成本。这也导致目前布线市场出现了一些性能较低的六类产品和方案。像某些厂家的六类线铜芯悄悄从</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">23AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">降至</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">24AWG</span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">，也是出于这种趋利的考虑。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;">
                                <br/></span></b><b style="mso-bidi-font-weight: normal;"><span style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: PMingLiU; mso-ascii-font-family: Arial; mso-font-kerning: 0pt; mso-bidi-font-family: Arial; mso-fareast-language: ZH-CN; mso-hansi-font-family: Arial;">　　我们认为，通过减少原材料的投入降低生产成本，以牺牲系统性能的代价来增强价格竞争力，是一种浮躁的短期现象，不利于布线企业长久健康发展。对于客户来说，在确定需求时，亦要根据自己应用的长远发展，合理规划定位真正性价比优良的布线系统。</span></b><b style="mso-bidi-font-weight: normal;"><span lang="EN-US" style="FONT-SIZE: 10.5pt; COLOR: blue; FONT-FAMILY: Arial; mso-font-kerning: 0pt; mso-fareast-language: ZH-CN;"><p></p></span></b></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span lang="EN-US" style="COLOR: blue; mso-fareast-font-family: 宋体; mso-fareast-language: ZH-CN;"><p><font face="Times New Roman" size="3">&nbsp;</font></p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; WORD-BREAK: break-all; LINE-HEIGHT: 24pt; mso-pagination: widow-orphan;"></p>

顶一下

<p>写的不错~~~超五六类同理~ </p>

不错，这帖子可以推荐加为精华了

希望楼主多发点这些知识，让我们也学习学习

谢谢！继续努力中......

<p>顶一下</p>

绝对好东东

如果感觉好，就多顶，这样才有心思收集更多更好的资料，供大家一起分享

顶下好帖

谢谢支持

+1

<p>向楼主请教一下：一个4连接点的信道模型是什么？？</p>

<p>对你的问题没理解意思？能麻烦你说的详细一点吗</p>